如果在演示物体的热膨胀现象的同时,对冷缩现象进行对比演示。现象更加有趣,这样,学生的印象会更加深刻,增强教学效果。本文介绍热胀和冷缩现象的对比演示装置。 1 金属材料的对比演示装置(图1) 演示说明:材料选用长25厘米左右,直径约2毫米的铜丝,用打火机给铜线加热;用棒冰或冰块作为冷缩实验的冷源,这样演示非常方便,现象也很稳定。 If you demonstrate the thermal expansion of an object, compare the cold shrink phenomenon. The phenomenon is more interesting. In this way, the student’s impression will be more profound and enhance the teaching effect. This article presents a contrast demonstration device for thermal expansion and contraction. 1 Comparison and demonstration device for metal materials (Figure 1) Demonstration: The material is a copper wire with a length of about 25 cm and a diameter of about 2 mm. The copper wire is heated with a lighter; the ice cold or ice is used as the cold source for the cold shrinkage test. The demonstration is very convenient and the phenomenon is very stable.